First, cpvc pipes can fail by several mechanisms, including high pressure, impact, environmental stress cracking. In plastics, this is a crazing, cracking, or fracturing in the presence of an incompatible environment and some form of stress. Spears cpvc cts pipe and fittings conform to astm d 2846 specification for chlorinated poly vinyl chloride cpvc plastic hot and cold water distribution systems. Chemical resistance pvc and cpvc thermoplastics are highly resistant to acids, alkalis, alcohols and many other corrosive materials. Mechanical stress cracking is the result of the piping being installed under high stress situations. Therefore oils used for cutting and pipe threading and all other petroleum based products can cause all plastics to develop cracks.
Exceeding the maximum pressure will cause the pipe walls to fail. The regulations include chemical contaminant health requirements, as well as long. Scc occurs as a result of a combination between corrosion and tensile stress. The study has shown that a mixture of ethylene glycol and propylene glycol is more damaging to cpvc pipe than either of the glycols by.
Spears evertuff cts cpvc pipe is easily joined using solvent. Each size and grade or schedule of pvc pipe is rated to a maximum fluid pressure. Spears thermoplastic piping system products are designed around primary components manufactured from pvc, cpvc or pp materials and their glass filled varieties. Cpvc pipe failure investigation community engineering services. Refer to appropriate nfpa standards concerning antifreeze systems and harvels installation instructions for additional information. We have been studying the causes of failure of cpvc piping systems for over a. Cpvc sprinkler pipe failure background a general contractor litigated against a number of his subcontractors when a fire sprinkler piping system in a new condominium building suffered numerous leaks in the chlorinated polyvinyl chloride cpvc distribution pipes.
Figure 1 shows an example of cracking that initiated at the inside surface of a cpvc pipe that was used for a fire suppression system that contained propylene glycol. Spears pvc pipe, fire sprinklers, flameguard, plastic. Cpvc corzan chlorinated polyvinyl chloride cpvc conforming to astm d1784, classification. Environmental stress cracking, also referred to as esc, is a mechanism by which an organic chemical possibly a weak solvent or even a nonsolvent achieves an extremely localized weakening at the surface. All cpvc schedule 80 pipe shall conform to astm f441f441m and be third party certified to nsf 14. Potential plumbing problems lurking in walls plumber. The stress induced in a pipe, which is restrained from expanding is calculated with the following formula. Cpvc compounds certified through nsfansi are compliant with the regulations established for potable water materials. What causes stress corrosion cracking in pipelines.
Pvc and cpvc materials can be easily joined by solvent cement welding plus threaded, flanged or mechanical coupled connections. Chemical resistance data from immersion tests cannot be unconditionally applied to thermoplastic piping components subjected to continuous or frequent mechanical or thermal stresses. Figure i shows an example of cracking that initiated at the inside surface of a cpvc pipe that was used for a fire suppression system that contained propylene glycol. Failure patterns were characterized and identified as environmental stress cracking esc caused by an external contaminant. Pipe expansion calculator for cpvc piping system design. Anyone who had issues with their flowguard gold cpvc pipes. Nonmetallic piping 9 thermoplastics pvdf 0 275 18 5 pvc 0 150 18 66 pp 30 210 1 99. It is critical to be able to determine if cpvc pipes and fittings were either the direct cause or a. Working pressure spears cpvc cts pipe and fittings have a continuous working pressure rating of 100 psi at 180 f 400 psi at 73 f. Potential damage to cpvc fire sprinkler systems from spray foam. If left unaccounted for during the design process, this expansion can cause compression stress on pipes and fittings, resulting in damage to industrial piping systems. Suitable for oilfree air handling to 25 psi, not for distribution of compressed air or gas page 336 due to material cost variations, prices subject to change. Diameter socket length minimum c entrance a bottom b tolerance a 18 0. Environmental stress cracking of commercial cpvc pipes.
Cpvc applications are for potable water distribution, corrosive fluid handling in industry, and fire suppression systems. A growing number of contractors believe that the risks of installing cpvc just arent worth it anymore. Apr 16, 2015 jeff grzetich, of plumb crazy plumbers in st. Chlorinated poly vinyl chloride cpvc is a thermoplastic pipe and fitting material made with cpvc compounds meeting the requirements of astm class 23447 as defined in astm specification d1784. Pvc is joined by solvent cementing, threading, or flanging. Pressure ratings pressure ratings of pipes and tubes and their fittings carbon steel, stainless steel, plastic, copper and more. Potential plumbing problems lurking in walls plumber magazine. One of the most common causes of cracking and splitting in pvc pipes is overpressurization. Corrosion is related to the susceptibility of the material to the environment, while stresses may be residual, external or. Our work has found that cpvc piping is incompatible with most hydrocarbon chemicals including the solvents in the cement used to make joints in the piping. A study has been made by the author to learn effects of single and of mixed glycols causing environmental stress cracking of cpvc pipes made by four different manufacturers from two different resin suppliers. This can include both cpvc process piping, through which the contaminated fluid may flow, or cpvc ducting drawing fumes from contaminated fluid. Over time the cpvc is getting brittle and cracking, so i no longer use it, he says.
Cpvc domestic water, fire sprinkler and industrial piping systems, have been used succesfully for more than 40 years in new construction and existing buildings. Like all piping materials, the most common mode of failure is improper design and poor craftsmanship. However, environmental stress cracking esc 2 issues with this antifreeze have been found when used with cpvc. Industry study of compatibility of spray polyurethane foam. Schedule 80 pvc technical information schedule 80 pvc. Environmental stress cracking esc and the second was the deformation of the piping due to excessive heat. Volume 8, issue 7 july 2011 environmental stress cracking of commercial cpvc pipes received 11 november 2009. Using incompatible thread pastes and pipe dopes is the major cause of environmental stress cracking in plastics.
Schedule 80 cpvc technical information schedule 80 cpvc. How to avoid environmental stress cracking in plastic piping corzan. Schedule 80 pvc and cpvc schedule 40 pvc technical manual. Mechanical stress cracking is defined as the external or internal cracks in a plastic caused by tensile stresses in excess of the local shortterm mechanical strength. When you install 100% steel fire sprinkler systems, you are guaranteed total compatibility. Effects of glycerin antifreeze on cpvc madison group. Caution areas chemical compatability veterans affairs. Cpvc is a reliable, robust, and inexpensive plumbing material that has gained wide acceptance in the construction industry. Challenges in investigating chlorinated polyvinyl chloride. Cpvc will fail when enough chains break or become sufficiently disentangled that a breach develops in the solid polymer. Schedule 80 cpvc technical information schedule 80 cpvc pipe.
Stress corrosion cracking scc is a type of environmentallyassisted cracking eac, or the formation of cracks caused by various factors combined with the environment surrounding the pipeline. With a design stress of 2,000 psi at 73f, the longterm hydrostatic strength of pvc is as high as any of the major thermoplastic materials being used for solid piping systems. Schedule 80 pvc and cpvc schedule 40 pvc technical. Lubrizol is a singlesource provider of polymer technologies designed to solve todays toughest building and production challenges, and is an innovator and world leader in chlorinated polyvinyl chloride cpvc resins and compounds. Fill out the form on this page and tell us your story. Certain chemicals can cause environmental stress cracking esc in pvc, cpvc, and abs piping materials. Spears thermoplastic piping system products are designed around primary. In plastics, this is a crazing, cracking, or fracturing in the presence of an incompatible environment and some form of.
Corzan cpvc high performance systems feature outstanding resistance to photodegradation, creep stress and immunity to oxidation, and are exceptionally suited for use with a wide range of acid, alcohols, salts and halogens. Improper installation, especially poor cementing techniques can lead to an abrupt release of tremendous stored energy. Due to their outstanding corrosion resistance cpvc products are ideally suited for these applications. Pvc has excellent chemical and corrosion resistance to a broad range of fluids. Cpvc pipe failure investigation community engineering.
Pvc and cpvc piping systems are not recommended for compressed air lines. What type of certification and documentation is required for the joining process of pvc and cpvc piping manufactured to asme b31. Both materials are ideal for process piping installation and most service piping applications. How cpvc works and why it fails leak damage can ultimately result in largeloss claims. Substitution of other products for spears evertuff cpvc marine pipe, fittings, or solvent. Spears pvc pipe, fire sprinklers, flameguard, plastic pipe. Cpvc pipe is an excellent alternative to copper pipe because of ease of installation, lower thermal conductivity and its resistance to corrosion. Before the attorneys can even consider filing a lawsuit, they. Progressive products from spears innovation and technology chemical resistance data for pressure piping chemical resistance this section is to provide information on the transport of various chemicals using pvc and cpvc thermoplastic piping materials. But when too many repiping jobs started requiring followup visits, he knew he had to find an alternative. Consult the sprinkler head manufacturer before using this product. Spears leadfree gasket sealed cts cpvc brassthreaded fittings are nsf certified in accordance with nsfansi 61. Schedule 80 pvc technical information schedule 80 pvc pipe. Cpvc fire sprinkler systems and spray foam insulation.
While common ordinary soaps are not detrimental to cpvc, most modern dishwashing liquids contain synthetic detergents, some of which may cause environmental stress cracking of cpvc. Tape sealants are far too frequently improperly or excessively applied. Available in a variety of nominal pipe sizes with 6 or 12 maximum travel. How cpvc works and why it fails propertycasualty360. With the corzan cpvc pipe expansion calculator, account for corzan cpvcs linear expansion and design around compression stress concerns. Petersburg, florida, used to install cpvc piping in homes. Can pvc or cpvc pipe be used for compressed air lines. Chemical compatibility and installation information for. Many of the risks associated with cpvc can be fully eliminated if systems use 100% steel fire sprinkler pipe. And unlike cpvc, if there is a leak, pexs warranty covers the damage to your home so you dont have to go through your homeowners insurance. Because the coefficient of thermal expansion of steel is five times lower than that of cpvc, dimensional change due to thermal expansion will be five times less.
Potential damage to cpvc copper tube size cts piping. Above those temperatures, both cpvc and pvc will begin to soften, increasing the risk of. Shattering of pipe and fittings is then apt to occur at directional changes and at point where the system is rigidly restrained due to instantaneous. This information is compiled from commercially available industry sources. Pipe expansion calculator for cpvc piping system design corzan.
Spears comprehensive line of cpvc fittings offers a variety of configurations in schedule 80 sizes 14 through 24. In order to position yourself to take advantage of the expected increase in demand for residential fire sprinkler systems, you need a provenreliable, costeffective, easytoinstall piping system material. Attorneys working with are investigating whether a defect in the pipes is causing them to fail and, if so, whether a class action lawsuit can be filed. Viking, harvel blazemaster, spears flameguard, and victaulic firelock.
Certain chemicals can cause environmental stress cracking esc in pvc, cpvc, and. Cpvc pipes operating and collapsing pressure ratings. Plasticizer contamination in the process fluid may also cause environmental stress cracking of cpvc used elsewhere in the system. Metal piping connected to or installed alongside cpvc piping. Systems from either environmental stress cracking esc or adverse.
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